Wireless Communication Method and Wireless Station

This application is a Continuation Application of U.S. Non-Provisional application Ser. No. 18/615,748 filed on Mar. 25, 2024, which is a continuation of International Patent Application No. PCT/CN2021/121107 filed on Sep. 27, 2021, the contents of which are herein incorporated by reference in their entirety.

The present disclosure relates to the field of communication systems, and more particularly, to a wireless communication method and a wireless station medium access recovery.

Communication systems such as wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (such as time, frequency, and power). A wireless network, for example, a wireless local area network (WLAN), such as a WI-FI (institute of electrical and electronics engineers (IEEE) 802.11) network may include an access point (AP) that may communicate with one or more wireless mobile stations (STAs) or devices. The WLAN enables a user to wirelessly access internet based on radio frequency technology in a home, an office, or a specific service area using a portable terminal such as a personal digital assistant (PDA), a laptop computer, a portable multimedia player (PMP), a smartphone, etc. The AP may be coupled to a network, such as the internet, and may enable a mobile device to communicate via the network (or communicate with other devices coupled to the AP). A wireless device may communicate with a network device bi-directionally. For example, in a WLAN, an STA may communicate with an associated AP via downlink and uplink. The downlink may refer to a communication link from the AP to the STA, and the uplink may refer to a communication link from the STA to the AP.

IEEE 802.11be WG has introduced a multi-link device (MLD) in a WLAN extreme high throughput (EHT) features and defined a multi-link (ML) discovery procedure for an STA affiliated with a non-AP MLD to solicit ML capabilities of APs affiliated with an AP MLD. An MLD is an IEEE 802.11 capable device and a logical entity, and has two or more affiliated stations (STAs), such as two or more non-AP STAs or APs, and a single medium access control (MAC) service access point (SAP) to logical link control (LLC), which includes one MAC data service.

IEEE 802.11be draft 1.1 has specified a medium access recovery procedure to address the blindness issue at a non-AP multi-link device (MLD) with a non-simultaneous transmit and receive (NSTR) pair.

The relevant rules of the medium access recovery procedure or mechanism comprise:

The problems in the current medium access recovery mechanism comprise:

For example, with reference to, an STAand an STAaffiliated with a non-AP MLDoperate on an NSTR pair, and an STAand an STAaffiliated with a non-AP MLDoperate on another NSTR pair. An APand an APare affiliated with an AP MLDWhen the APtransmits a trigger frame to solicit TB PPDUs from the STAaffiliated with MLDand the STAaffiliated with MLDthe STAand the STAstart their MediumSyncDelay timers respectively. According to the currently specified rules when the STAtransmits an RTS frameas the first frame of any attempt to obtain a TXOP, the STAresets its MediumSyncDelay timer mistakenly on time Tbased on the RTS frame, even though there is no response to the RTS frame detected.

Hence, it is desirable to provide a wireless communication method and a wireless device to address the problems in the current standards.

An object of the present disclosure is to propose a wireless communication method and a wireless station.

A first aspect of the disclosure provides a wireless communication method including: a wireless station (STA) affiliated with a multi-link device (MLD), which has a nonzero medium synchronization delay (i.e. MediumSyncDelay) timer, when receiving a physical protocol data unit (PPDU) with a valid media access control PDU (MPDU) that contains a request to send (RTS) frame or a multi-user RTS (MU-RTS) trigger frame, determining whether to reset the medium synchronization delay timer to zero according to detecting of the PPDU; or

A second aspect of the disclosure provides a STA. The STA includes a processor, and the processor is configured to call and run a computer program stored in a memory, to cause a device in which a chip is installed to execute a method. The method includes: the STA affiliated with an MLD, which has a nonzero MediumSyncDelay timer, when receiving a PPDU with a valid MPDU that contains a RTS frame or an MU-RTS trigger frame, determining whether to reset the MediumSyncDelay timer to zero according to detecting of the PPDU. Alternatively, the method includes: the STA, that supports an operation for a control frame including a medium access recovery subfield, transmitting a control frame including a medium access recovery subfield indicating whether the control frame is sent by the STA that has a nonzero MediumSyncDelay timer if needed.

A third aspect of the disclosure provides a computer readable storage medium, in which a computer program is stored. The computer program causes a computer to execute a method, and the method includes: a STA affiliated with an MLD, which has a nonzero MediumSyncDelay timer, when receiving a PPDU with a valid MPDU that contains a RTS frame or an MU-RTS trigger frame, determining whether to reset the MediumSyncDelay timer to zero according to detecting of the PPDU. Alternatively, the method includes: a STA, that supports an operation for a control frame including a medium access recovery subfield, transmitting a control frame including a medium access recovery subfield indicating whether the control frame is sent by the STA that has a nonzero MediumSyncDelay timer if needed.

Embodiments of the present disclosure are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. Specifically, the terminologies in the embodiments of the present disclosure are merely for describing the purpose of the certain embodiment, but not to limit the disclosure.

illustrates an example of a wireless communications system according to an embodiment of the present disclosure. The wireless communications system may be an example of a wireless local area network (WLAN)configured in accordance with various aspects of the present disclosure. The WLAN is also known as a WI-FI network, such as extremely high throughput (EHT), high-efficiency (HE), very high throughput (VHT), and high-throughput (HT) Wi-Fi network. As described herein, the terms extremely high throughput (EHT), high-efficiency (HE), very high throughput (VHT), and high-throughput (HT) may be considered synonymous and may each correspond to a Wi-Fi network supporting a high volume of space-time-streams. The WLANmay include an APand multiple associated STAs, which may represent devices such as mobile stations, personal digital assistant (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (such as TVs, computer monitors, etc.), printers, etc. The APand the associated stationscan communicate through WLAN connectionsand may represent a basic service set (BSS) or an extended service set (ESS). The various STAsin the network can communicate with one another through the AP. Also illustrated is a coverage areaC of the AP, which may represent a basic service area (BSA) of the WLAN. An extended network station (not shown) associated with the WLANmay be connected to a wired or wireless distribution system that may allow multiple APsto be connected in an ESS.

In some embodiments, an STAmay be located in the intersection of more than one coverage areaC and may associate with more than one AP. A single APand an associated set of STAsmay be referred to as a BSS. An ESS is a set of connected BSSs. A distribution system (not shown) may be used to connect APsin an ESS. In some cases, the coverage areaC of an APmay be divided into sectors (not shown). The WLANmay include APsof different types (such as a metropolitan area, home network, etc.), with varying and overlapping coverage areasC. Two STAsalso may communicate directly via a direct wireless linkregardless of whether both STAsare in the same coverage areaC. Examples of direct wireless linksmay include Wi-Fi direct connections, Wi-Fi tunneled direct link setup (TDLS) links, and other group connections. STAsand APsmay communicate according to the WLAN radio and baseband protocol for physical and media access control (MAC) layers from IEEE 802.11 and versions including, but not limited to, 802.11b, 802.11g, 802.11a, 802.11n, 802.11ac, 802.11ad, 802.11ah, 802.11ax, 802.11ay, etc. In some other implementations, peer-to-peer connections or ad hoc networks may be implemented within the WLAN.

illustrates one or more stations (STAs)and an access point (AP)of communication in a wireless communications systemaccording to an embodiment of the present disclosure.illustrates that, the wireless communications systemincludes an access point (AP)and one or more stations (STAs). The APmay include a memory, a transceiver, and a processorcoupled to the memoryand the transceiver. The one or more STAsmay include a memory, a transceiver, and a processorcoupled to the memoryand the transceiver. The processorormay be configured to implement proposed functions, procedures and/or methods described in this description. Layers or sublayers of radio interface protocol may be implemented in the processoror. The memoryoris operatively coupled with the processororand stores a variety of information to operate the processoror. The transceiveroris operatively coupled with the processoror, and the transceiverortransmits and/or receives a radio signal.

The processorormay include application-specific integrated circuit (ASIC), other chipset, logic circuit and/or data processing device. The memoryormay include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and/or other storage device. The transceiverormay include baseband circuitry to process radio frequency signals. When the embodiments are implemented in software or computer programs, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the memoryorand executed by the processoror. The memoryorcan be implemented within the processororor external to the processoror. Solutions in which memory can be communicatively coupled to the processororvia various means as are known in the art.

In some embodiments, the processoris configured to perform the disclosed method in the embodiments of the invention.

IEEE 802.11be Draft 1.1 has specified the medium access recovery procedure. According to the medium access recovery procedure, a first STA, such as the STA, and a second STA, such as the STA, are affiliated with a non-AP MLD, such as the non-AP MLD, that belong to an NSTR link pair. The first STA is considered to have lost medium synchronization due to uplink (UL) interference when the second STA, which is affiliated with the same non-AP MLD and belongs to the NSTR link pair, transmits a PPDU, except when both STAs ended a transmission at the same time.

The first STA that has lost medium synchronization due to a transmission event initiated by the second STA affiliated with the same MLD starts a MediumSyncDelay timer at the end of the transmission event if the transmission event is longer than aMediumSyncThreshold. The aMediumSyncThreshold is a pre-configured parameter for medium synchronization threshold in the standards. The first STA may not start the

MediumSyncDelay timer if the transmission event is shorter than or equal to aMediumSync Threshold.

The MediumSyncDelay timer is a single timer, shared by all enhanced distributed channel access functions (EDCAFs) within a non-AP STA, which is initialized to aPPDUMax Time defined in Table 36-69 in the standards, for extremely high throughput (EHT) physical layer (PHY) characteristics. The STA shall update its MediumSyncDelay timer to the one contained in a medium synchronization field, if present, of the basic variant multi-Link element in the most recent frame received from an associated AP MLD, such as AP MLD. The medium synchronization delay timer resets to zero when any of the following events occur:

The first STA affiliated with the non-AP MLD that has a nonzero MediumSyncDelay timer that supports to obtain a TXOP may perform:

An AP affiliated with an AP MLD may include the Medium Synchronization Delay Information field in a Basic variant Multi-Link element carried in an Association Response, Beacon, or Probe Response frame. An AP affiliated with an AP MLD shall not include the Medium Synchronization Delay Information field in a Basic variant Multi-Link element carried in an Authentication frame. An STA affiliated with a non-AP MLD shall not include the Medium Synchronization Delay Information field in any Basic variant Multi-Link element it transmits.

A non-AP STA shall initialize dot11MSDOFDMEDthreshold to −72 dBm and MSD_TXOP_MAX to 1, respectively. The non-AP STA affiliated with the non-AP MLD shall set MSD_TXOP_MAX and dot11MSDOFDMEDthreshold to the most recent values in the Medium Synchronization Maximum Number Of TXOPs and Medium Synchronization OFDM ED Threshold subfields, respectively, if they are present in a Basic variant Multi-Link element received from its associated AP MLD.

Note that if either the intra-BSS NAV or the inter-BSS NAV is nonzero in the non-AP STA affiliated with the non-AP MLD when it starts the MediumSyncDelay timer, the non-AP STA does not initiate any TXOP and follow the same rules as an HE STA to respond to any RTS or MU-RTS frame until both NAVs expire. NAV stands for a network allocation vector (NAV).

In the standards during the aCCAtime (see 36.3.20.6.3 (CCA sensitivity for occupying the primary 20 MHz channel)) immediately following the end of the transmission event that caused loss of medium synchronization and subsequent initiation of the MediumSyncDelay timer at the non-AP STA, if the received signal strength exceeds the CCA-ED threshold as given by dot11OFDMEDThreshold for the primary 20 MHz channel and no start of a PPDU is detected, the non-AP STA should defer for extended interframe space (EIFS) beginning when the received signal strength falls below the CCA-ED threshold.

The application provides embodiments of the invention to address the problems in the current specification of medium access recovery procedure in IEEE 802.11be Draft 1.1.

The following description is directed to certain embodiments for the purposes of describing the innovative aspects of the present disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The described implementations may be implemented in any device, system, or network that is capable of transmitting and receiving radio frequency (RF) signals according to any of the IEEE 802.11 standards, the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), global system for mobile communications (GSM), GSM/general packet radio service (GPRS), enhanced data GSM environment (EDGE), terrestrial trunked radio (TETRA), wideband-CDMA (W-CDMA), evolution data optimized (EV-DO), 1×EV-DO, EV-DO Rev A, EV-DO Rev B, high speed packet access (HSPA), high speed downlink packet access (HSDPA), high speed uplink packet access (HSUPA), evolved high speed packet access (HSPA+), long term evolution (LTE), AMPS, or other known signals that are used to communicate within a wireless, cellular or internet of things (IOT) network, such as a system utilizing 3G, 4G, or 5G, or further implementations thereof, technology. Standards in the description may at least refer to one or more versions of the IEEE 802.11 specifications.

IEEE 802.11be Draft 1.1 has specified the medium access recovery mechanism to handle the blindness issue at NSTR non-AP MLD. One potential solution to handle this issue is to specify the rule as follows:

This solution, however, is incomplete. For example, the medium synchronization delay timer can reset to zero when the RTS frame is sent by an STA which has zero MediumSyncDelay timer or has no MediumSyncDelay timer. The current rules for NSTR soft AP MLD is specified as follows:

This would lead to a problem. For example, an STA affiliated with an NSTR soft AP MLD, which has a nonzero MediumSyncDelay timer is operating on a non-primary link. The STA cannot directly transmit an RTS frame as the initial frame of an obtained TXOP if the other STA in a primary link has not gained a TXOP for transmission.

For example, with reference to, an STAand an STAaffiliated with a non-AP MLDhave their respective nonzero MediumSyncDelay timers. An APand an APare affiliated with an AP MLD

The APaffiliated with an NSTR soft AP MLDwhich has a nonzero MediumSyncDelay timer is operating on a non-primary link Link. The APcannot directly transmit an RTS frame as the initial frame of an obtained TXOP if the other AP (i.e., AP) affiliated with the NSTR soft AP MLDin a primary link has not gained a TXOP for transmission.

The innovation proposes some solutions to solve the problems existing in the current specification of medium access recovery mechanism in IEEE 802.11be Draft 1.1.

With reference to, a wireless station (STA) supports an operation for a control frame including a medium access recovery subfield (step S). The STA transmits a control frame including a medium access recovery subfield indicating whether the control frame is sent by the STA that has a nonzero medium synchronization delay timer (step S). In an embodiment of the invention, the control frame including the medium access recovery subfield is a multi-user RTS (MU-RTS) trigger frame. In another embodiment of the invention, the control frame including the medium access recovery subfield is a RTS frame.

The wireless device starts a medium synchronization delay timer at an end of a blindness period of the wireless device to time a medium synchronization delay period when the wireless device affiliated with a non-access point multi-link device (non-AP MLD) that belongs to a wireless link pair has lost medium synchronization, wherein the medium synchronization delay timer times the medium synchronization delay period. The medium synchronization delay timer may comprise the MediumSyncDelay timer, and the medium synchronization delay period may comprise the MediumSyncDelay period timed by the MediumSyncDelay timer. The wireless device detects the wireless link pair for a transmission event on at least one link of the wireless link pair to obtain a detection result.

With reference to, a wireless station (STA) is affiliated with a multi-link device (MLD), which has a medium synchronization delay timer (step S). The STA receives a physical protocol data unit (PPDU) with a valid media access control PDU (MPDU) that contains a request to send (RTS) frame or a multi-user RTS (MU-RTS) trigger frame (step S). The STA determines whether to reset the medium synchronization delay timer to zero according to detecting of the PPDU (step S).

The wireless device determines whether to adjust the medium synchronization delay period based on the detection result. The wireless device may adjust the medium synchronization delay period by starting, resetting, or restarting the medium synchronization delay timer. The wireless device may determine a first corresponding rule to adjust the medium synchronization delay period according to the detection result and apply the first corresponding rule accordingly.

A first STA, such as the STA, that has lost medium synchronization due to a transmission event performed by a second STA, such as the STA, affiliated with the same MLD, such as the non-AP MLD, starts the MediumSyncDelay timer at the end of the transmission event if the transmission event is longer than the aMediumSyncThreshold. The first STA may use one or several or all of the following solutions or rules in the embodiments during the period of the MediumSyncDelay timer when the MediumSyncDelay is not equal to 0.

In the following, STAs,, andare examples of the STA. AP,, andare examples of the AP.

In an embodiment of the invention, the control frame including the medium access recovery subfield is a multi-user RTS (MU-RTS) trigger frame.

A Medium Access Recovery subfield in the Common Info field of the MU-RTS Trigger frame indicates whether the MU-RTS Trigger frame is sent by an STA that has a nonzero MediumSyncDelay timer. A value of 1 in the Medium Access Recovery subfield indicates that the MU-RTS Trigger frame is sent by an STA that has a nonzero MediumSyncDelay timer. Otherwise, a value of 0 in the Medium Access Recovery subfield indicates that the MU-RTS Trigger frame is sent by an STA that has a zero MediumSyncDelay timer, or has no MediumSyncDelay timer.

For example, optional EHT variant Common Info field formats of a Trigger frame contain the Medium Access Recovery subfield for the MU-RTS Trigger frame are shown into. The Medium Access Recovery subfield is present in an MU-RTS Trigger frame.

In an embodiment of the invention, the one or more of following rules in Table 1 are included in a medium access recovery mechanism:

A first value, such as 1, in the medium access recovery subfield indicates that the MU-RTS Trigger frame is sent by the STA that has a nonzero medium synchronization delay. A second value, such as 0, in the medium access recovery subfield indicates that the MU-RTS Trigger frame is sent by the STA that has a zero medium synchronization delay timer (e.g., the MediumSyncDelay timer), or does not has any medium synchronization delay timer (e.g., the MediumSyncDelay timer).

According to at least one of the rules, the STA is a non-AP STA affiliated with a non-access-point (non-AP) multi-link device (MLD), and the non-AP STA has a nonzero medium synchronization delay timer (e.g., the MediumSyncDelay timer) and supports to obtain a TXOP. The STA transmits an MU-RTS Trigger frame in which a value of the medium access recovery subfield is the first value, as the first frame of any attempt to obtain a TXOP.

According to at least one of the rules, the STA doesn't reset the medium synchronization delay timer (e.g., the MediumSyncDelay timer) to zero when the STA receives a PPDU with a valid MPDU that contains an MU-RTS Trigger frame in which a value of the medium access recovery subfield is the first value. The STA resets the medium synchronization delay timer (e.g., the MediumSyncDelay timer) to zero when the STA receives a PPDU with a valid MPDU that contains an MU-RTS Trigger frame in which a value of the medium access recovery subfield is the second value.